As an electromagnetic contact device on which is mounted an ancillary unit, for example, the apparatus described in Patent Reference 1 is known. This apparatus is a reversible-type electromagnetic contact apparatus connected to a feed circuit of an induction motor and capable of forward/reverse operation control of the induction motor; two electromagnetic contact devices are connected via a mechanical interlock unit (reversible unit) which prohibits simultaneous input of the electromagnetic contact devices.    Patent Reference 1: Japanese Patent Laid-open No. 2006-100027